"Selfish Routing"

Pete Kruckenberg pete at kruckenberg.com
Fri Feb 14 22:34:45 UTC 2003


http://www.scienceblog.com/community/article1018.html

---
"The Internet is 'fault-tolerant,' so there are always many 
routes a message can take. A packet of data traveling from 
New York to San Francisco might go by way of Chicago or 
Dallas, or might even hop from New York to Columbus to Miami 
to Omaha to Denver to San Francisco.

"Routers have many ways to decide. Sometimes they send out 
test packets and time them. Sometimes routers exchange 
information about the condition of the network in their 
vicinities. But if routers choose the route that looks the 
least congested, they are doing selfish routing. As soon as 
that route clogs up, the routers change their strategies and 
choose other, previously neglected routes.

"Roughgarden has a suggestion that wouldn't be expensive to 
implement. Before deciding which way to send information, he 
says, routers should consider not only which route seems the 
least congested, but also should take into account the 
effect that adding its own new messages will have on the 
route it has chosen. That would be, he says, 'just a bit 
altruistic' in that some routers would end up choosing 
routes that were not necessarily the fastest, but the 
average time for all users would decrease."
---

This might be easier to understand if it was more technical,
but I'm only aware of a lot of disabled features on my
routers that are supposed to in theory do some of these
things. 

Abstractions and analogies aside, is this really a problem,
and is it really worth solving? Sounds like a lot of
additional complexity for the supposed benefits.

Pete.




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